449PD - Relative abundance of EGFR mutations predict tumor metastasis and EGFR-TKIs prognosis in patients with non-small cell lung cancer

Date 17 December 2016
Event ESMO Asia 2016 Congress
Session Thoracic cancers
Topics Anti-Cancer Agents & Biologic Therapy
Biomarkers
Non-Small-Cell Lung Cancer, Metastatic
Presenter he Zhen
Citation Annals of Oncology (2016) 27 (suppl_9): ix139-ix156. 10.1093/annonc/mdw594
Authors H. Zhen1, Q. Wang1, H. Wang1, H. Tang1, Z. Zhang1, Y. Wu1, L. Wang1, D. Zhao1, L. Yang1, B. Wei2, J. Ma2, Y. Guo2
  • 1Medical Oncology, Henan Provincial Anti-Cancer Hospital, 450008 - Zhengzhou/CN
  • 2Molecular Pathology, Henan Provincial Anti-Cancer Hospital, 450008 - Zhengzhou/CN

Abstract

Background

Epidermal growth factor receptor (EGFR) has been confirmed to be an effective biomarker in EGFR-TKIs treatment for NSCLC. Previous studies have demonstrated EGFR mutation abundance could predict benefit from EGFR-TKIs treatment. Here we aimed to explore potential effect of EGFR mutation abundance on tumor metastasis and EGFR-TKIs prognosis.

Methods

3913 patients from Henan Cancer Hospital diagnosed with NSCLC were enrolled. The EGFR mutation abundance in tumor specimens was quantified by amplification refractory mutation system (ARMS). Above 10% was defined as high abundance, and below 10% was defined as low abundance.

Results

The ratio of high mutation abundance in age < 60 years group was significantly higher than that in age ≥ 60 years group (55.4% vs. 42.5%, P = 0.000). Whereas the distribution of EGFR mutation abundance was no difference between surgery and biopsy specimens (P = 1.000). Additionally, the ratio of high abundance in 19 exon deletion was obviously higher than that in L858R and rare mutations (66.5% vs. 31.6% vs. 51.1%, P = 0.000). Meanwhile, the ratio of high abundance in patients with hepar metastasis was significantly higher than that in patients without hepar metastasis (57.2% vs. 47.8%, P = 0.036), but that in brain or bone metastasis was demonstrated no significant difference (P = 0.897 and P = 0.293, respectively). The subgroup analysis among above metastasis patients indicated the ratio of high abundance in 19 exon deletion was significantly higher that in L858R. Furthmore, the difference in median PFS between 19 exon deletion and L858R group was significant (17.5 months vs. 9.2 months, P = 0.003).

Conclusions

The younger patients more likely harbor high EGFR mutation abundance. Hepar metastasis status was associated with EGFR mutation abundance. Median PFS in 19 exon deletion patients was notablely longer than that in L858R group for EGFR-TKIs treatment, which may refer to high abundance in 19 exon deletion.

Clinical trial indentification


Legal entity responsible for the study

Zhen He

Funding

N/A

Disclosure

All authors have declared no conflicts of interest.